Optical disk device

ABSTRACT

An optical disk device includes: an optical disk drive mechanism disposed in a housing-shape drive case ( 2 ), the optical disk drive mechanism including an optical head ( 7 ) on which a semiconductor laser ( 5 ) is mounted, a rotary driver for driving an optical disk ( 8 ), and a transfer mechanism for transferring the optical head ( 7 ); and an agitating fan ( 12 ) for making air in the drive case ( 2 ) flow. In the optical disk device, a wind path is formed so that the air in the drive case ( 2 ) flows in a manner in which it is drawn toward an agitating fan ( 12 ) side and the drawn air is discharged toward the optical head ( 7 ) or the semiconductor laser ( 5 ) by rotation of the agitating fan ( 12 ). Therefore, a rise in temperature of the semiconductor laser ( 5 ) can be suppressed effectively, while the dust proofing is ensured.

TECHNICAL FIELD

The present invention relates to an optical disk device on which anoptical disk drive is mounted.

BACKGROUND ART

Generally, if dust continuously enters an optical disk drive, the dustadheres to an optical system of an optical head, in particular, anobjective lens, and an amount of light emitted from the optical head isreduced progressively. When the amount of light is reducedprogressively, amplitudes of a recording/reproducing signal as well as afocusing control signal and a tracking control signal for the objectivelens deteriorate continuously, and finally the system fails, so that itbecomes impossible to perform recording/reproduction. On this account,to ensure the reliability of the optical disk drive, it is necessary totake dust-proofing measures to prevent the entry of dust as much aspossible, such as hermetically sealing the optical disk drive.

On the other hand, an optical disk device on which the optical diskdrive is mounted is equipped with parts as sources of heat generation,such as a disk motor, an optical head transfer motor, a semiconductorlaser mounted on the optical head, a drive circuit for driving theseelements, and a power source.

When the optical disk drive is sealed hermetically for the purpose ofthe dust-proofing measures as described above, heat from the respectiveheat generation sources is unlikely to be transferred, and the heatremains to be accumulated there. In particular, in the case of thesemiconductor laser, there is a correlation between an operatingtemperature environment and the lifetime, and the lifetime of theelement is shortened when it is used at a high temperature. Accordingly,it is desirable that this element is operated in an environment of aslow a temperature as possible. However, in a recording operation usingthe element with a high power, the heat generated from the elementitself becomes high.

Moreover, due to the hermetically sealed optical disk drive, the heat isaccumulated, and the temperature of the element is raised beyond aguaranteed temperature range of the element set in consideration of thelifetime. Consequently, to ensure a sufficient reliability of thedevice, it is indispensable to take measures to radiate the heat fromthe semiconductor laser.

As a solution to the conflicting problems of dust-proofing andheat-radiation measures, an optical disk sub-system device is proposedin JP 8(1996)-102180A, for example. The optical disk sub-system deviceincludes an optical disk drive, a power source for driving the opticaldisk drive, and a cooler for cooling the inside of a housing. In thedevice, the housing internally is partitioned into a first chamber and asecond chamber by a sill plate, and the first chamber in which theoptical disk drive and the cooler are disposed is sealed hermetically,and the cooler forms an internal air circulation path.

According to this conventional example, since the first chamber issealed hermetically, the optical disk drive disposed therein is freefrom an adverse effect due to dust. In addition, since the coolercirculates air in the first chamber, a temperature distribution in thefirst chamber gradually is made homogeneous, and a temperature of asemiconductor laser mounted on an optical head also is reduced.

However, in this configuration, the internal air circulation path isformed in the hermetically sealed first chamber so as to form an airflowthroughout the first chamber. While this airflow has an effect ofcausing heat transfer by which the temperature distribution in thechamber is made uniform, the heat transfer due to air cooling generallyis effected more efficiently as an amount and speed of the airflow arehigher.

Accordingly, when the amount or speed of the airflow is low with respectto an amount of heat generated from a heat source, the heat radiationeffect with respect to the heat source is also small. The semiconductorlaser has the lowest heat resistance among elements of the optical disk,and is a heat source. Thus, to suppress a rise in temperature of thesemiconductor laser is the most effective way to improve the thermalreliability and durability of the device.

According to the device disclosed in JP 8(1996)-102180 A, the airflow isformed throughout the first chamber, and thus it is a part of theairflow generated by a fan in flow amount and flow speed that reachesthe semiconductor laser. With this configuration, it is less efficientin suppressing the rise in temperature of the semiconductor laser, and asufficient heat radiation effect cannot be achieved. In this case, toincrease the heat radiation effect with respect to the semiconductorlaser, it is required to increase the flow amount by using a fan havinga large diameter, and to increase the flow speed by increasing therotation rate of the fan.

However, when the diameter of the fan is increased, the device becomeslarger, resulting in a loss of saleability. Thus, there is a limit tothe increase in the flow amount. Further, when the rotation rate of thefan is increased, the noise of the fan becomes higher, resulting in aloss of saleability. In addition, heat generation of the fan itself isincreased, which reduces the heat radiation effect. Thus, there is alsoa limit to the increase in the flow speed.

As described above, with the configuration of JP 8(1996)-102180 A, thereis a limit to the achievement of a desired heat radiation effect withrespect to the semiconductor laser, and it is impossible to ensure thethermal reliability and durability of the device.

Moreover, in the device of the above-described conventional example,since the air circulation path is formed to pass through a place otherthan the area in which the optical disk drive is configured, the entiredevice becomes larger, resulting in a loss of saleability.

DISCLOSURE OF INVENTION

The present invention has been made to solve the conventional problemsas described above, and its object is to provide an optical disk devicethat has an improved thermal reliability and durability by suppressing arise in temperature of a semiconductor laser through efficient heattransfer, while ensuring the dust proofing by hermetically sealing anoptical disk drive.

To achieve the above object, an optical disk device of the presentinvention includes: an optical disk drive mechanism disposed in ahousing-shape drive case, the optical disk drive mechanism including anoptical head on which a semiconductor laser is mounted, a rotary driverfor driving an optical disk, and a transfer mechanism for transferringthe optical head; and an agitating fan for making air in the drive caseflow. In the optical disk device, a wind path is formed so that the airin the drive case flows in a manner in which it is drawn toward anagitating fan side and the drawn air is discharged toward the opticalhead or the semiconductor laser by rotation of the agitating fan.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a front view schematically showing an internal structure of anoptical disk device according to Embodiment 1 of the present invention.

FIG. 2 is a plan view schematically showing the internal structure ofthe optical disk device shown in FIG. 1.

FIG. 3 is a view showing an experimental result with respect to theoptical disk device according to Embodiment 1 of the present invention.

FIG. 4 is a plan view schematically showing an internal structure of anoptical disk device according to Embodiment 2 of the present invention.

FIG. 5 is a plan view schematically showing an internal structure of anoptical disk device according to Embodiment 3 of the present inventionin the state where an optical head 7 is located on an innercircumference side of an optical disk 8.

FIG. 6 is a plan view schematically showing an internal structure of theoptical disk device according to Embodiment 3 of the present inventionin the state where the optical head 7 is located on an outercircumference side of the optical disk 8.

FIG. 7 is a plan view schematically showing an internal structure of anoptical disk device according to Embodiment 4 of the present invention.

FIG. 8 is a front view schematically showing the internal structure ofthe optical disk device shown in FIG. 7.

FIG. 9 is a side view schematically showing the internal structure ofthe optical disk device shown in FIG. 7.

FIG. 10 is a front view schematically showing an internal structure ofthe optical disk device shown in FIG. 7 when a first optical head 26 isoperated.

FIG. 11 is a side view schematically showing the internal structure ofthe optical disk device in the state shown in FIG. 10.

FIG. 12 is a front view schematically showing an internal structure ofthe optical disk device shown in FIG. 7 when a second optical head 32 isoperated.

FIG. 13 is a side view schematically showing the internal structure ofthe optical disk device in the state shown in FIG. 12.

FIG. 14 is a side view schematically showing an internal structure of anoptical disk device according to Embodiment 5 of the present invention.

BEST MODE FOR CARRYING OUT THE INVENTION

According to the present invention, an optical head is set in a drivecase so that the dust proofing is ensured, and air that is drawn fromthe inside of the drive case and is discharged from an agitating fan isblown toward the optical head or a semiconductor laser, whereby a risein temperature of the semiconductor laser can be suppressed effectively,while the dust proofing is ensured.

In the optical disk device of the present invention, it is preferablethat the drive case is disposed in a housing-shape main body case, themain body case internally being partitioned into the drive case and adeck area having an air hole for outside air, and a drive circuit fordriving the optical disk drive mechanism and a power source for thedrive circuit are disposed in the deck area. With this configuration,the deck area can be cooled with the outside air introduced from the airhole of the deck area, so that transfer of heat generated from the drivecircuit and the power source to the inside of the drive case can besuppressed.

It is preferable that the drive case is disposed in a housing-shape mainbody case, the main body case internally being partitioned into thedrive case and a deck area having an air hole for outside air, theoptical head is constituted by a first optical head on which ashort-wavelength semiconductor laser is mounted, and a second opticalhead on which a long-wavelength semiconductor laser is mounted. Theoptical disk drive mechanism includes the first and second opticalheads, a first transfer mechanism for transferring the first opticalhead, a second transfer mechanism for transferring the second opticalhead, and rotary drivers provided independently for the respective firstand second transfer mechanisms for driving the optical disk. The firstand second transfer mechanisms are disposed in parallel with each otherin a direction perpendicular to a transfer direction of the first andsecond optical heads, and in parallel with a surface of the optical diskmounted on either of the rotary drivers. A drive circuit for driving theoptical disk drive mechanism, and a power source for the drive circuitare disposed in the deck area, and the agitating fan is disposed at aposition opposed to the first transfer mechanism so that the airdischarged from the agitating fan flows initially to the first transfermechanism and then to the second transfer mechanism.

With this configuration in which the first and second optical heads areprovided, since the first transfer mechanism for the short-wavelengthsemiconductor laser is disposed on a side nearer to the agitating fan,the short-wavelength semiconductor laser in which a temperature rise isgreater than that of the long-wavelength semiconductor laser can becooled efficiently.

Further, the deck area can be cooled with the outside air introducedfrom the air hole of the deck area, so that transfer of heat generatedfrom the drive circuit and the power source to the inside of the drivecase can be suppressed.

It is preferable that the short-wavelength semiconductor laser isdisposed on a side face of the first optical head that is nearer to theagitating fan in the direction perpendicular to the transfer directionof the first optical head. With this configuration, the short-wavelengthsemiconductor laser can be cooled more efficiently.

It is preferable that the long-wavelength semiconductor laser isdisposed on a side face of the second optical head that is nearer to theagitating fan in the direction perpendicular to the transfer directionof the second optical head. With this configuration, the long-wavelengthsemiconductor laser can be cooled more efficiently.

It is preferable that in a recording/reproducing operation with thesecond optical head, a position of the first transfer mechanism isvaried so that the air discharged from the agitating fan can be blowntoward the second optical head directly. With this configuration, evenin the operation of the second optical head located farther from theposition of the agitating fan, the airflow discharged from the agitatingfan is blown toward the long-wavelength semiconductor laser directlywithout being raised in temperature nor being reduced in flow speed bybeing blocked by a shield, whereby the long-wavelength semiconductorlaser can be cooled efficiently.

It is preferable that the wind path is formed so that air below theoptical head is drawn, and the drawn air is discharged through theagitating fan toward the optical head or the semiconductor laser. Withthis configuration, low-temperature air below the optical head is blowntoward the optical head or the semiconductor laser, whereby cooling canbe performed efficiently.

It is preferable that a suction port for drawing the air in the drivecase, and a discharge port for discharging the air in the drive case areformed on a side wall of the drive case, and the wind path is formed bya wind tube that connects the suction port and the discharge port andextends toward an outside of the drive case, and the agitating fan isdisposed in the wind tube. With this configuration, the wind tube isdisposed so as to extend toward the outside of the drive case, wherebythe space in the deck area can be utilized effectively, and theagitating fan can be provided without making the device larger.

It is preferable that the wind tube is covered with a heat insulatingmaterial. With this configuration, it is possible to prevent air passingthrough the wind tube from being raised in temperature by heat from acircuit substrate or a power source disposed in the deck area. Thus,even in a recording operation using the semiconductor laser with a highpower, the temperature of the semiconductor laser can be kept low.

It is preferable that a cooler for cooling air passing through the windtube is included. With this configuration, the cooling effect achievedby the agitating fan can be increased, and a decrease in the coolingeffect due to an ambient temperature condition can be suppressed.

It is preferable that the cooler is an air system. With thisconfiguration, the structure is made simple.

It is preferable that the cooler is a heat pipe or a highly thermalconductive material attached to the wind tube. With this configuration,the cooling effect achieved by the agitating fan is increasedexcellently.

It is preferable that the cooler is a Peltier element. With thisconfiguration, the cooling effect achieved by the agitating fan isincreased excellently.

It is preferable that the agitating fan is disposed so that the airdischarged from the agitating fan is blown toward the optical head orthe semiconductor laser over a full movable range of the optical head.With this configuration, the temperature of the semiconductor laseralways can be kept low.

It is preferable that a duct is disposed so that the air discharged fromthe agitating fan is blown toward the optical head or the semiconductorlaser over a full movable range of the optical head. With thisconfiguration, the temperature of the semiconductor laser always can bekept low.

It is preferable that the duct is a wind directing plate, a tilt angleof which is varied in conjunction with movement of the optical head in aradial direction of the optical disk, and the variation in the tiltangle allows a direction of an airflow discharged from the agitating fanto follow the movement of the optical head. With this configuration,even if the optical head is located at any position within a movablerange, the airflow discharged from the agitating fan is blown toward thesemiconductor laser directly, whereby the temperature of thesemiconductor laser always is kept low.

It is preferable that a dust collecting filter is provided forcollecting dust in the drawn air. With this configuration, dust in thedrive case is eliminated when the air is drawn by the agitating fan, andas the suction is performed continuously, a cleaner environment isformed in the drive case.

It is preferable that a shield is provided on a straight line between aposition from which an airflow discharged from the agitating fan isdischarged to an inside of the drive case and an objective lens mountedon the optical head for focusing light of the semiconductor laser. Withthis configuration, a flow of air blown toward the objective lens can bedisturbed before the objective lens, and thus dust included in the aircan be prevented from being adhered to the objective lens.

Hereinafter, embodiments of the present invention will be described withreference to the drawings.

EMBODIMENT 1

FIG. 1 is a front view schematically showing an internal structure of anoptical disk device according to Embodiment 1 of the present invention,and FIG. 2 is a plan view schematically showing the internal structureof the optical disk device as shown in FIG. 1. In FIGS. 1 and 2, ahousing-shape drive case 2 is mounted in a housing-shape main body case1. The main body case 1 internally is partitioned into a deck area 3 anda drive area 4 by the drive case 2. The drive area 4 is sealedhermetically from outside air by the drive case 2.

As shown in FIG. 2, an optical head 7 is disposed in the drive area 4,and the optical head 7 is supported by guide shafts 11 a and 11 b. Asemiconductor laser 5 as a light source for performingrecording/reproduction, and an objective lens 6 for focusing light fromthe semiconductor laser 5 are mounted on the optical head 7. The guideshaft 11 a is a screw shaft, and has its end portion connected to arotation axis of a feed motor 10. The guide shafts 11 a and 11 b, andthe feed motor 10 configure an optical head transfer mechanism.

An optical disk 8 is provided by being chucked on a disk motor 9 as arotary driver. The optical disk 8 is irradiated with the light focusedby the objective lens 6. The optical head 7, the disk motor 9, and theabove-described optical head transfer mechanism configure an opticaldisk drive mechanism.

In the present embodiment, while not shown in the figures, a loadingmechanism for carrying the optical disk 8 placed on a tray in the drivecase 2 and carrying it out of the drive case 2, and a mechanism foropening and closing the drive case 2 for the carrying in and out areprovided.

As shown in FIG. 1, a suction port 12 a is provided at the bottom on aside face of the drive case 2. A discharge port 12 b is formed on top ofthe suction port 12 a. The suction port 12 a and the discharge port 12 bare connected by a wind tube 12 c. The wind tube 12 c is adhered to thedrive case 2 so as not to lose the hermeticity of the drive area 4. Anagitating fan 12 is provided in the wind tube 12 c.

The wind tube 12 c is disposed so as to extend toward the outside of thedrive case 2. Thus, the space in the deck area 3 can be utilizedeffectively, and the agitating fan 12 can be provided without making thedevice larger.

By rotation of the agitating fan 12, air in the drive case 2 is drawnthrough the suction port 12 a at the bottom of the drive case 2 towardthe agitating fan 12, and is discharged to the inside of the drive case2 from the upper discharge port 12 b.

Since the agitating fan 12 and the semiconductor laser 5 are disposed soas to be opposed to each other, the airflow discharged from theagitating fan 12 is blown toward the semiconductor laser 5 directly.

In the deck area 3, a drive circuit 13 for driving the optical diskdrive mechanism is disposed above the drive case 2. A power source 14for supplying the drive circuit 13 with a power is disposed on a side ofa side face of the drive case 2.

The operation of the optical disk device thus configured will bedescribed more specifically. When the optical disk 8 is mounted on thedisk motor 9, and the optical disk device starts a recording/reproducingoperation, the power source 14 itself generates heat. Further, the powersource 14 supplies a power to the semiconductor laser 5, the disk motor9 for rotationally driving the optical disk 8, the feed motor 10 forgenerating a driving force to transfer the optical head 7 in a radialdirection of the optical disk 8, and the drive circuit 13 for drivingthe optical disk drive mechanism. Accordingly, these elements alsogenerate heat.

As shown in FIG. 2, a deck fan 15 is attached at a position of anexhaust hole 19 formed in the main body case 1, and air holes 16 areprovided on a lower surface of the main body case 1. The deck fan 15 andthe power source 14 are disposed in parallel with each other in adirection of a rotation axis of the deck fan 15. Further, as shown inFIG. 1, the deck fan 15 and the power source 14 are disposed in parallelwith each other in a vertical direction seen from a front side of thedeck fan 15.

By rotation of the deck fan 15, outside air is taken in the deck area 3from the air holes 16, and the air in the deck area 3 is exhausted tothe outside of the main body case 1 through the exhaust hole 19. Sincethe drive circuit 13 and the power source 14 are located in thisairflow, the heat generated therefrom is transferred to the air suppliedcontinuously from the outside, and this air is exhausted to the outside.

Consequently, the deck area 3 is cooled, and transfer of the heatgenerated from the drive circuit 13 and the power source 14 to theinside of the drive case 2 can be suppressed as much as possible.Further, due to the positional relationship between the deck fan 15 andthe power source 14 as described above, heated air whose temperature hasbeen raised due to the heat generation of the power source 14 can beexhausted efficiently.

On the other hand, in the drive case 2, the semiconductor laser 5, thedisk motor 9, and the feed motor 10 generate heat, thereby effecting atemperature distribution. In this case, the heat from the semiconductorlaser 5 as a light source has a tendency to be transferred upward due tonatural heat radiation, and thus the drive area 4 has a lowertemperature in a lower area than in an upper area in a height directionthereof.

Low-temperature air in the lower area is drawn through the suction port12 a, and is blown from the discharge port 12 b toward the opposedsemiconductor laser 5 directly by the rotation of the agitating fan 12.As a result, the heat from the semiconductor laser 5 can be radiatedforcibly. In this case, since the semiconductor laser 5 and thedischarge port 12 b are opposed to each other, the low-temperature airin the lower area is blown toward the semiconductor laser 5 in the statewhere the wind generated by the agitating fan 12 has the highest flowamount and flow speed. Therefore, efficient heat transfer is caused, anda rise in temperature of the semiconductor laser 5 is suppressedeffectively.

The air blown toward the semiconductor laser 5 flows in the upper areaof the drive case 2, flows back to the lower area, and is drawn throughthe suction port 12 a again. In other words, the rotation of theagitating fan 12 allows forced convection of the air in the drive case2, so that it flows from the lower area to the upper area, and furtherfrom the upper area to the lower area. As a result, a rise intemperature of the disk motor 9 and the feed motor 10 as light sourcesother than the semiconductor laser 5 also can be suppressed.

Further, even if the optical head 7 is located at any position within amovable range in a radial direction (direction of an arrow a shown inFIG. 2) of the optical disk 8 ranging from an inner circumference to anouter circumference, the temperature of the semiconductor laser 5 alwayscan be kept low by making the airflow discharged from the agitating fan12 be blown toward the semiconductor laser 5. This can be realized byadjusting the disposed position of the agitating fan 12. Morespecifically, adjustment of the disposed position of the agitating fan12 in the radial direction of the optical disk 8, the distance betweenthe agitating fan 12 and the semiconductor laser 5, or the size of thedischarge port 12 b are performed.

As described above, according to the present embodiment, a rise intemperature of the semiconductor laser 5 can be suppressed effectivelywithout making the device larger, while the dust proofing is ensured byhermetically sealing the drive case 2. Therefore, even in a recordingoperation using the semiconductor laser 5 with a high power, thetemperature of the element can be kept low, and thus the lifetime of theelement can be increased, whereby an optical disk device having a highreliability and durability with respect to heat and dust can berealized.

In the present embodiment, while the airflow discharged from theagitating fan is blown toward the semiconductor laser, the dischargedairflow is blown not only toward the semiconductor laser but also towardthe optical head in the vicinity thereof. Thus, the cooling effect alsois increased with respect to an LSI and circuit components for drivingthe semiconductor laser disposed in the vicinity of the semiconductorlaser. This also applies to the following embodiments.

As described above, in the present embodiment, the main body case 1internally is partitioned into the hermetically sealed drive area 4 andthe deck area 3 having permeability to outside air by the drive case 2.Therefore, the dust proofing is ensured in the drive area 4, and thedust proofing of an optical system of the optical head 7, in particular,the objective lens 6 also is ensured.

However, when the optical disk is loaded and unloaded, a part of thedrive case 2 is opened. Accordingly, dust may enter the drive area 4,and an optical disk to which dust is attached may be taken in the drivearea 4.

When the optical disk 13 as a commutative medium to which dust isattached is mounted on the disk motor 9, the dust is diffused in thedrive case 2 by air agitated by rotation of the optical disk 13 or anairflow generated by the agitating fan 12.

In the present embodiment, as shown in FIG. 1, a dust collecting filter17 is attached to the suction port 12 a, so that the dust is eliminatedby the dust collecting filter 17 when air is drawn through the suctionport 12 a. By repeating this operation, a cleaner environment is formedin the drive case 2.

In the case where a part of the dust is not eliminated even after theair passes through the dust collecting filter 17, or where dust floatingin the drive case 2 is involved in the airflow from the discharge port12 b, the dust may be attached to the objective lens 6. In the presentembodiment, a shield 18 is provided on the optical head 7 on a straightline between the discharge port 12 b and the objective lens 6. Thus, thedischarged airflow blown toward the objective lens 6 can be disturbedbefore the objective lens, so that the dust included in the dischargedairflow is prevented from being attached to the objective lens 6.

Hereinafter, a description will be given of an experiment performed toconfirm the effect of the present embodiment. FIG. 3 is a graph showingthe result of the experiment, wherein a horizontal axis indicates a timet (minute) elapsed from the start of an operation, and a horizontal axisindicates a temperature T (° C.). An interval shown with t1 is aninterval for which the operation of the agitating fan 12 is stopped, andan interval shown with t2 is an interval for which the agitating fan 12is operated. A line 50 indicates a temperature of the semiconductorlaser 5, a line 51 indicates a temperature in an upper space in thedrive case 2, and a line 52 indicates a temperature in a lower space inthe drive case 2.

With respect to the interval t1, the temperature in the space in thedrive case 2 hardly is varied even with the elapse of time. To thecontrary, the temperature of the semiconductor laser 5 is raised withthe elapse of time, resulting in a maximum temperature difference ofapproximately 20° C. between the temperatures of the semiconductor laserand that in the lower space in the drive case 2.

On the other hand, with respect to the interval t2 for which theagitating fan 12 is operated, the temperature of the semiconductor laser5 decreases sharply, and becomes almost stable at a value approximately12° C. lower than its maximum value in the interval t2 after the elapseof 100 minutes.

Such a significant drop in temperature is ascribed to the fact that airin the lower space in the drive case 2 whose temperature is about 20° C.lower than that of the semiconductor laser 5 is blown toward thesemiconductor laser 5 directly. Accordingly, the effect of the presentembodiment was confirmed.

EMBODIMENT 2

(65) FIG. 4 is a plan view schematically showing an internal structureof an optical disk device according to Embodiment 2 of the presentinvention. In FIG. 4, parts operated in the same way as those shown inFIG. 2 are denoted by the same reference numerals.

In FIG. 4, a duct 19 is provided in the vicinity of the discharge port12 b. The duct 19 is disposed so as to allow an airflow discharged fromthe discharge port 12 b to flow toward the semiconductor laser 5.

In the configuration shown in FIG. 4, although the semiconductor laser 5and the discharge port 12 b are not disposed so as to be opposed to eachother, the duct 19 allows the direction of the discharged airflow to bevaried, so that the airflow discharged from the agitating fan 12 can beblown toward the semiconductor laser 5 directly. Also in thisconfiguration, air in a lower area of the drive case 2 is drawn andblown toward the semiconductor laser 5 directly as in Embodiment 1.

The duct 19 can be formed of a flat plate member, and it is possible tovary the direction of the discharged airflow with a simple structure.

According to the present embodiment, even in the case where thesemiconductor laser 5 and the discharge port 12 b are not opposed toeach other, the provision of the duct 9 allows the discharged airflow tobe blown toward the semiconductor laser 5 directly with a simplestructure, resulting in the same effect as that in Embodiment 1.

EMBODIMENT 3

FIGS. 5 and 6 are plan views schematically showing internal structuresof an optical disk device according to Embodiment 3 of the presentinvention. In FIGS. 5 and 6, parts operated in the same way as thoseshown in FIG. 2 are denoted by the same reference numerals. FIG. 5 showsthe state where the optical head 7 is located on an inner circumferenceside of the optical disk 8, and FIG. 6 shows the state where the opticalhead 7 is located on an outer circumference side of the optical disk 8.

A wind directing plate 20 forming a duct is configured such that twoslats 20 a and 20 b are connected by a connecting plate 20 c, resultingin a parallel link. One end of each of the two slats 20 a and 20 b isfixed to the drive case 2 so as to be capable of turning, and the otherend is fixed to the connecting plate 20 c so as to be capable ofturning. Such fixing can be realized by engaging a protruding pin with ahole provided in each of the slats 20 a and 20 b. The connecting plate20 c is fixed to the optical head 7, and thus is moved in conjunctionwith the optical head 7.

As shown in FIG. 5, when the optical head 7 is moved toward the innercircumference side of the optical disk 8, a driving force in atranslational direction acts on the connecting plate 20 c by themovement of the optical head 7, so that the slats 20 a and 20 b turntoward the inner circumference side of the optical disk 8, resulting inthe formation of a duct directed from the discharge port 12 b to thesemiconductor laser 5. Accordingly, an airflow discharged from thedischarge port 12 b is blown toward the semiconductor laser 5 directly.

As shown in FIG. 6, when the optical head 7 is moved toward the outercircumference side of the optical disk 8, the slats 20 a and 20 b turntoward the outer circumference side of the optical disk 8, resulting inthe formation of a duct directed from the discharge port 12 b to thesemiconductor laser 5. Accordingly, an airflow discharged from thedischarge port 12 b is blown toward the semiconductor laser 5 directly.

According to the present embodiment, the wind directing plate 20 turnsin conjunction with the movement of the optical head 7, so that a tiltangle of the wind directing plate 20 is varied, whereby the direction ofthe airflow discharged from the agitating fan 12 is varied. Thevariation in the tilt angle allows the direction of the dischargedairflow to follow the movement of the optical head 7. Therefore, even ifthe optical head 7 is located at any position in a movable range, theairflow discharged from the agitating fan 12 can be blown toward thesemiconductor laser 5 directly, whereby the temperature of thesemiconductor laser 5 always is kept low.

Further, since the wind directing plate 20 forms the duct capable ofcontrolling the direction of the wind, almost the entire dischargedairflow can be blown toward the semiconductor laser 5 directly. Thus,more efficient heat transfer can be caused, and a rise in temperature ofthe semiconductor laser 5 can be suppressed more effectively.Furthermore, since it is possible to utilize the capability of theagitating fan 12 efficiently as described above, the agitating fan 12can be made smaller, and accordingly the device can be made smaller.

EMBODIMENT 4

FIG. 7 is a plan view schematically showing an internal structure of anoptical disk device according to Embodiment 4 of the present invention.FIG. 8 is a front view schematically showing the internal structure ofthe optical disk device shown in FIG. 7. FIG. 9 is a side viewschematically showing the internal structure of the optical disk deviceshown in FIG. 7.

FIG. 10 is a front view schematically showing an internal structure ofthe optical disk device shown in FIG. 7 when a first optical head 26 isoperated. FIG. 11 is a side view schematically showing the internalstructure of the optical disk device in the state shown in FIG. 10.

FIG. 12 is a front view schematically showing an internal structure ofthe optical disk device shown in FIG. 7 when a second optical head 32 isoperated. FIG. 13 is a side view schematically showing the internalstructure of the optical disk device in the state shown in FIG. 12.

As shown in FIG. 7, a drive case 22 is mounted in a main body case 21 ofthe optical disk device. The main body case 21 internally is partitionedinto a deck area 23 and a drive area 24 by the drive case 22. The drivearea 24 is sealed hermetically from outside air.

In the drive area 24, the first optical head 26 on which a blue laser 25as a light source for recording/reproduction with a short wavelength ismounted is disposed and supported by first guide shafts 29 a and 29 b.The first guide shaft 29 a is a screw shaft, and has its end portionconnected to a rotation axis of a first feed motor 28.

An optical disk 45 for the blue laser is chucked on a first disk motor27 as a rotary driver, and is driven rotationally. The first disk motor27, the first guide shafts 29 a and 29 b supporting the first opticalhead 26, and the first feed motor 28 are fixed on a first transfer base30. Theses elements configure a first transfer mechanism 53.

The second optical head 32 on which a red laser 31 as a light source forrecording/reproduction with a long wavelength is mounted is disposed andsupported by second guide shafts 35 a and 35 b. The second guide shaft35 a is a screw shaft, and has its end portion connected to a rotationaxis of a second feed motor 34.

An optical disk 46 (see FIG. 12) for the red laser is chucked on asecond disk motor 33 as a rotary driver, and is driven rotationally. Thesecond disk motor 33, the second guide shafts 35 a and 35 b supportingthe second optical head 32, and the second feed motor 34 are fixed on asecond transfer base 36. Theses elements configure a second transfermechanism 54.

The first transfer base 30 and the second transfer base 36 are disposedin parallel with each other in a direction (direction of an arrow b)perpendicular to a transfer direction of the first and second transferbases 30 and 36, in a plane parallel to a surface of the blue laseroptical disk 45 or the red laser optical disk 46, and are supported by ahoisting/lowering turning axis 47 so as to freely turn independently.

In the above-described configuration, the first and second optical heads26 and 32, the first and second disk motors 27 and 33, and the first andsecond transfer mechanisms 53 and 54 configure an optical disk drivemechanism.

While not shown in the figures, a loading mechanism for carrying theblue laser optical disk 45 and the red laser optical disk 46 placed on atray in the drive case 22 and carrying them out of the drive case 22independently, and a mechanism for opening and closing the drive case 22for the carrying in and out are provided.

As shown in FIG. 8, a suction port 38 is provided at the bottom on aside face of the drive case 22. A discharge port 39 is formed on top ofthe suction port 38. The suction port 38 and the discharge port 39 areconnected by a wind tube 40. The wind tube 40 is adhered to the drivecase 22 so as not to lose the hermeticity of the drive area 24. Anagitating fan 37 is provided in the wind tube 40.

The wind tube 40 is disposed so as to extend toward the outside of thedrive case 22. Thus, the space in the deck area 23 can be utilizedeffectively, and the agitating fan 37 can be provided without making thedevice larger.

The discharge port 39 and the blue laser 25 are disposed so as to beopposed to each other so that an airflow discharged from the dischargeport 39 is blown toward the blue laser 25 directly. Further, aprotruding portion in which the wind tube 40 is formed is covered with aheat insulating material 48.

As shown in FIG. 8, in the deck area 23 in the case main body 21, acircuit substrate 41 for driving the first and second transfermechanisms is disposed below the drive case 22, and a power source 42for supplying the circuit substrate 41 with a power is disposed on aside of a side face of the drive case 22.

The operation of the optical disk device thus configured will bedescribed more specifically.

As shown in FIG. 7, in a recording/reproducing operation with the firstoptical head 26, the blue laser optical disk 45 is mounted on the diskmotor 27, and the optical disk device starts the recording/reproducingoperation. In this state, the second optical head 32 is in anon-operational state, and as shown in FIG. 10, the second transfer base36 turns about the hoisting/lowering turning axis 47 to be inclined, sothat the second optical head 32 is located at a position lowered from aposition in the recording/reproducing operation.

When the recording/reproducing operation with the first optical head 26is started, the power source 42 itself generates heat. Further, thepower source 42 supplies a power to the blue laser 25 of the opticalhead 7, the first disk motor 27 for rotationally driving the opticaldisk 45, the first feed motor 28 for generating a driving force totransfer the first optical head 26 in a radial direction of the opticaldisk 45, and the drive circuit 41 for driving the optical disk drivemechanism. Accordingly, these elements also generate heat.

As shown in FIG. 7, a deck fan 43 is attached at a position of anexhaust hole 49 formed in the housing 21, and air holes 44 are providedon a lower surface of the housing 21. The deck fan 43 and the powersource 42 are disposed in parallel with each other in a direction of arotation axis of the deck fan 43. Further, as shown in FIG. 8, the deckfan 43 and the power source 42 are disposed in parallel with each otherin a vertical direction seen from a front side of the deck fan 43.

By rotation of the deck fan 43, outside air is taken in the deck area 23from the air holes 44, and the air in the deck area 23 is exhausted tothe outside of the housing 21 through the exhaust hole 49.

Since the circuit substrate 41 and the power source 42 are located inthis airflow, the heat generated therefrom is transferred to the airsupplied continuously from the outside, and this air is exhausted to theoutside. Consequently, the deck area 23 is cooled, and transfer of theheat generated from the circuit substrate 41 and the power source 42 tothe inside of the drive case 22 is suppressed as much as possible.

Further, due to the positional relationship between the deck fan 43 andthe power source 42 as described above, heated air whose temperature hasbeen raised due to the heat generation of the power source 42 can beexhausted efficiently.

Furthermore, since the wind tube 40 is covered with the heat insulatingmaterial 48, it is possible to prevent air passing through the wind tube40 from being raised in temperature by the heat from the circuitsubstrate 41 or the power source 42 disposed in the deck area 23. Thus,even in a recording operation using the semiconductor laser with a highpower, the temperature of the semiconductor laser can be kept low.

On the other hand, in the drive case 22, the blue laser 25, the firstdisk motor 27, and the first feed motor 28 generate heat, therebyeffecting a temperature distribution. In this case, the heat from theblue laser 25 as a light source has a tendency to be transferred upwarddue to natural heat radiation, and thus the drive area 24 has a lowertemperature in a lower area than in an upper area in a height directionthereof

As shown in FIG. 10, low-temperature air in the lower area is drawnthrough the suction port 38, and is blown from the discharge port 39toward the opposed blue laser 25 directly by rotation of the agitatingfan 37. As a result, the heat from the blue laser 25 can be radiatedforcibly. In this case, since the blue laser 25 and the discharge port39 are opposed to each other, the low-temperature air in the lower areais blown toward the blue laser 25 in the state where the wind generatedby the agitating fan 37 has the highest flow amount and flow speed.Therefore, efficient heat transfer is caused, and a rise in temperatureof the blue laser 25 is suppressed effectively.

The air blown toward the blue laser 25 flows in the upper area of thedrive case 22, flows back to the lower area, and is drawn through thesuction port 38 again. In other words, the rotation of the agitating fan37 allows forced convection of the air in the drive case 22, so that itflows from the lower area to the upper area, and further from the upperarea to the lower area. As a result, a rise in temperature of the firstdisk motor 27 and the first feed motor 28 as heat sources other than theblue laser 25 also can be suppressed.

Further, even if the first optical head 26 is located at any positionwithin a movable range, the temperature of the blue laser 25 always canbe kept low by making the airflow discharged from the agitating fan 37be blown toward the blue laser 25. This can be realized by adjusting thedisposed position of the agitating fan 37. More specifically, adjustmentof the disposed position of the agitating fan 37 in the radial directionof the optical disk, the distance between the agitating fan 37 and thesemiconductor laser 25, or the size of the discharge port 39 areperformed.

While the first and second optical heads 26 and 32 are disposed inparallel with each other, the first optical head 26 for the blue laser25 is disposed on a side nearer to the agitating fan 37. Further, theblue laser 25 is disposed on a side face of the first optical head 26that is nearer to the agitating fan 37 in a direction perpendicular to atransfer direction of the first optical head 26. Consequently, theshort-wavelength blue laser 25 in which a temperature rise is greaterthan that of the red laser 31 can be cooled efficiently.

In a recording/reproducing operation with the second optical head 32,the blue laser optical disk 46 (FIG. 12) is mounted on the second diskmotor 33 shown in FIG. 7. When the optical disk device starts therecording/reproducing operation, the power source 42 itself generatesheat. Further, the power source 42 supplies a power to the red laser 31,the second disk motor 33 for rotationally driving the optical disk 46,the second feed motor 34 for generating a driving force to transfer thesecond optical head 32 in a radial direction of the optical disk 46, andthe drive circuit 41 for driving the optical disk drive mechanism.Accordingly, these elements also generate heat.

In this state, the first optical head 26 is in a non-operational state,and as shown in FIG. 12, the first transfer base 30 turns about thehoisting/lowering turning axis 47 to be inclined, so that the firstoptical head 26 is located at a position lowered from a position in therecording/reproducing operation.

By rotation of the deck fan 43, air flows from the air holes 44 to thedeck fan 43 in the deck area 23. Therefore, transfer of the heatgenerated from the circuit substrate 41 and the power source 42 to theinside of the drive case 22 can be suppressed. This is the same as inthe case where the first optical head 26 is operated.

In the drive case 22, the red laser 31, the second disk motor 33, andthe second feed motor 34 generate heat, thereby effecting a temperaturedistribution. In this case, the heat from the light source has atendency to be transferred upward due to natural heat radiation, andthus the drive area 24 has a lower temperature in a lower area than inan upper area in a height direction thereof.

Here, the first optical head 26 is in a non-operational state asdescribed above, and a rise in temperature caused by the first opticalhead 26 itself is not observed around the first optical head 26.Further, as shown in FIGS. 12 and 13, the first optical head 26 turnsdownward about the turning axis 47. Furthermore, the red laser 31 isdisposed on a side face of the second optical head 32 that is nearer tothe agitating fan 37 in a direction perpendicular to a transferdirection of the second optical head 32.

Therefore, the airflow discharged from the agitating fan 37 is blowntoward the red laser 31 directly through a space made above the firstoptical head 26 as shown in FIG. 12 without being raised in temperaturenor being reduced in flow speed by being blocked by a shield. In otherwords, low-temperature air in the lower area of the drive case 22 isdrawn through the suction port 38, and is blown from the discharge port39 toward the opposed red laser 31 directly by rotation of the agitatingfan 37. As a result, the heat from the red laser 31 can be radiatedforcibly.

The air blown toward the red laser 31 flows back to the lower area, andis drawn through the suction port 38 again. In other words, the rotationof the agitating fan 37 allows forced convection of the air in the drivecase 22, so that it flows from the lower area to the upper area, andfurther from the upper area to the lower area. As a result, a rise intemperature of the second disk motor 33 and the second feed motor 34 asheat sources other than the red laser 31 also can be suppressed.

In the present embodiment, the two-head unit is used. As describedabove, even in the operation of the optical head for the red laserlocated at a position farther from the agitating fan 37, the airflowdischarged from the agitating fan 37 is blown toward the red laser 31directly through the space made above the first optical head 26 withoutbeing raised in temperature nor being reduced in flow speed by beingblocked by a shield. Thus, there is no need to provide an additionalagitating fan 37 particularly, and the single agitating fan 37 issufficient, whereby upsizing of the device can be suppressed.

Further, the dust proofing of the drive area 24 is ensured, and the dustproofing of an optical system of the optical heads 26 and 32, inparticular, an objective lens also is ensured as in Embodiment 1.

As described above, the two-head unit is used in the present embodiment.However, as in Embodiment 1, a rise in temperature of the semiconductorlaser can be suppressed effectively without making the device larger,thereby realizing an optical disk device having a high reliability anddurability with respect to heat and dust.

Embodiment 5

FIG. 14 is a side view schematically showing an internal structure of anoptical disk device according to Embodiment 5 of the present invention.In the figure, parts operated in the same way as those shown in FIG. 8are denoted by the same reference numerals.

In the configuration of the present embodiment, a protruding portion inwhich the wind tube 40 is formed is covered with a highly thermalconductive material 53, and a heat-radiating fin 55 is adhered to theoutside of the highly thermal conductive material with a Peltier element54 sandwiched therebetween.

Due to the thermoelectric conversion effect of the Peltier element 54,the highly thermal conductive material 53 is cooled, so that air passingthrough the wind tube 40 can be cooled forcibly. Heat generated from thePeltier element 54 itself is transferred to the heat-radiating fin 55,and is radiated by the wind generated by the deck fan 43.

With this configuration, the air cooled forcibly is discharged from thedischarge port 39 to the inside of the drive case 22, whereby the bluelaser 25 or the red laser 31 can be cooled forcibly regardless of anambient temperature condition.

Therefore, even in a recording operation using the blue laser 25 and thered laser 31 with a high power, the temperature of the laser element canbe kept low, and thus the lifetime of the element can be increased.

While the present embodiment has been described by way of an example inwhich the Peltier element 53 is used as a cooler, the heat-radiating fin55 may be provided alone. Further, a heat pipe or a highly thermalconductive material may be combined with the heat-radiating fin. Withthis configuration, heat transfer is accelerated by the heat pipe or thehighly thermal conductive material, thereby increasing the coolingeffect.

Further, while the present embodiment has been described by way of anexample in which the first transfer mechanism and the second transfermechanism are provided, the present embodiment also may be applied to aconfiguration with only one transfer mechanism.

While Embodiment 1 has been described by way of an example in which thedust collecting filter 17 is provided, the dust collecting filter may beprovided in any of Embodiments 2 to 5.

While in Embodiment 2 and Embodiment 3, the descriptions have been givenof the configuration in which the duct 19 is provided, and of theconfiguration in which the wind plate 20 is provided, respectively,theses configurations may be provided in any of Embodiments 1, 4, and 5.

While in Embodiment 4, the description has been given of theconfiguration in which the wind tube 40 is covered with the heatinsulating material 48, this configuration may be applied to any ofEmbodiments 1 to 3.

While in Embodiment 1, the description has been given of theconfiguration in which the shield 18 is provided on the optical head 7on a straight line between the discharge port 12 b and the objectivelens 6, this configuration may be provided in any of Embodiments 2 to 5.

INDUSTRIAL APPLICABILITY

As described above, according to the present invention, a rise intemperature of a semiconductor laser can be suppressed effectivelywithout making a device larger, while the dust proofing is ensured,whereby a high reliability and durability with respect to heat and dustcan be realized. Consequently, the present invention is available as anoptical disk device for recording/reproducing information using anoptical disk as an information recording medium for images, music,computer data, and the like.

1. An optical disk device, comprising: an optical disk drive mechanismdisposed in a housing-shape drive case, the optical disk drive mechanismincluding an optical head on which a semiconductor laser is mounted, arotary driver for driving an optical disk, and a transfer mechanism fortransferring the optical head; and an agitating fan for making air inthe drive case flow, wherein a wind path is formed so that the air inthe drive case flows in a manner in which it is drawn toward anagitating fan side and the drawn air is discharged toward the opticalhead or the semiconductor laser by rotation of the agitating fan.
 2. Theoptical disk device according to claim 1, wherein the drive case isdisposed in a housing-shape main body case, the main body caseinternally being partitioned into the drive case and a deck area havingan air hole for outside air, and a drive circuit for driving the opticaldisk drive mechanism and a power source for the drive circuit aredisposed in the deck area.
 3. The optical disk device according to claim1, wherein the drive case is disposed in a housing-shape main body case,the main body case internally being partitioned into the drive case anda deck area having an air hole for outside air, the optical head isconstituted by a first optical head on which a short-wavelengthsemiconductor laser is mounted, and a second optical head on which along-wavelength semiconductor laser is mounted, the optical disk drivemechanism includes the first and second optical heads, a first transfermechanism for transferring the first optical head, a second transfermechanism for transferring the second optical head, and rotary driversprovided independently for the respective first and second transfermechanisms for driving the optical disk, the first and second transfermechanisms are disposed in parallel with each other in a directionperpendicular to a transfer direction of the first and second opticalheads, and in parallel with a surface of the optical disk mounted oneither of the rotary drivers, a drive circuit for driving the opticaldisk drive mechanism, and a power source for the drive circuit aredisposed in the deck area, and the agitating fan is disposed at aposition opposed to the first transfer mechanism so that the airdischarged from the agitating fan flows initially to the first transfermechanism and then to the second transfer mechanism.
 4. The optical diskdevice according to claim 3, wherein the short-wavelength semiconductorlaser is disposed on a side face of the first optical head that isnearer to the agitating fan in the direction perpendicular to thetransfer direction of the first optical head.
 5. The optical disk deviceaccording to claim 3, wherein the long-wavelength semiconductor laser isdisposed on a side face of the second optical head that is nearer to theagitating fan in the direction perpendicular to the transfer directionof the second optical head.
 6. The optical disk device according toclaim 3, wherein in a recording/reproducing operation with the secondoptical head, a position of the first transfer mechanism is varied sothat the air discharged from the agitating fan can be blown toward thesecond optical head directly.
 7. The optical disk device according toclaim 1, wherein the wind path is formed so that air below the opticalhead is drawn, and the drawn air is discharged through the agitating fantoward the optical head or the semiconductor laser.
 8. The optical diskdevice according to claim 1, wherein a suction port for drawing the airin the drive case, and a discharge port for discharging the air in thedrive case are formed on a side wall of the drive case, and the windpath is formed by a wind tube that connects the suction port and thedischarge port and extends toward an outside of the drive case, and theagitating fan is disposed in the wind tube.
 9. The optical disk deviceaccording to claim 8, wherein the wind tube is covered with a heatinsulating material.
 10. The optical disk device according to claim 8,comprising a cooler for cooling air passing through the wind tube. 11.The optical disk device according to claim 10, wherein the cooler is anair system.
 12. The optical disk device according to claim 10, whereinthe cooler is a heat pipe or a highly thermal conductive materialattached to the wind tube.
 13. The optical disk device according toclaim 10, wherein the cooler is a Peltier element.
 14. The optical diskdevice according to claim 1, wherein the agitating fan is disposed sothat the air discharged from the agitating is blown toward the opticalhead or the semiconductor laser over a full movable range of the opticalhead.
 15. The optical disk device according to claim 1, wherein a ductis disposed so that the air discharged from the agitating fan is blowntoward the optical head or the semiconductor laser over a full movablerange of the optical head.
 16. The optical disk device according toclaim 15, wherein the duct is a wind directing plate, a tilt angle ofwhich is varied in conjunction with movement of the optical head in aradial direction of the optical disk, and the variation in the tiltangle allows a direction of an airflow discharged from the agitating fanto follow the movement of the optical head.
 17. The optical disk deviceaccording to claim 1, wherein a dust collecting filter is provided forcollecting dust in the drawn air.
 18. The optical disk device accordingto claim 1, wherein a shield is provided on a straight line between aposition from which an airflow discharged from the agitating fan isdischarged to an inside of the drive case and an objective lens mountedon the optical head for focusing light of the semiconductor laser.